In the city’s new rules allowing the use of smartphones to hail yellow cabs, regulators inserted a provision that requires any e-hailing app to be “integrated” with the existing meter and credit card terminals in New York’s 13,000 taxis.

But one of the app makers vying to offer an e-hailing service in the city has formally asked to be released from that rule, saying that it has struggled to hammer out technical details with one of the vendors who supply credit card terminals for New York’s cabs.

Hailo Network USA Inc. filed a request for a waiver of the integration rule on Friday afternoon, a company spokesman said. A spokesman for the Taxi and Limousine Commission said the commission had received but not reviewed the waiver request and would not say how quickly David Yassky, the commission chairman, would rule on it.

If Yassky were to agree to Hailo’s request to launch its system using its current technology, it could potentially jump-start e-hails in New York, especially since the company made its request on behalf of it and its competitors. But such a decision is far from assured. The apps became legal to use on Friday, but app makers are still working out the kinks of integration with the meter and payment systems, and a lawsuit filed Thursday by livery and black car owners seeks to block the use of the smartphone apps altogether.

The waiver request has revealed a private spat that had been growing between Hailo and VeriFone Inc., one of the vendors that provides so called TPEP systems — the combined taxi meter, touchscreen and credit card terminals that are required for all New York taxis.

In a draft of the waiver request reviewed by The Wall Street Journal, Hailo complains that one of the TPEP vendors — VeriFone — has been “uncooperative” as the app developers try to make their software fit with the taxi system. A person familiar with Hailo’s discussions said the company had not butted heads with the other TPEP vendor, Creative Mobile Technologies LLC.

In a statement, a VeriFone spokesman said the company had been “actively working with applicants” for months, had scheduled a developers conference to address technical questions about integration earlier this year, and had struck agreements with multiple developers for access to the company’s data feed from taxis.

Representatives from other e-hail companies said this week that they had not experienced undue difficulty in their negotiations with VeriFone or CMT.

At the root of the conflict and Hailo’s waiver request is a regulatory puzzle. E-hailing services — like Hailo, and those offered by developers like Uber Technologies Inc., Flywheel Software Inc., RideCharge Inc. and others — have flourished in other cities around the globe, with varying degrees of conflict with local regualtors.

But New York’s highly regulated marketplace has presented unique challenges. In the e-hail rules approved late last year, the TLC approved a compromise. It allowed app makers that are already processing the fares and payments of taxi customers in other cities to begin operating in New York. But it made them process payments through the existing taxi systems – the TPEP machines provided by CMT and VeriFone.

Hailo and its backers are now asking the TLC to let them bypass the VeriFone and CMT systems altogether.

“As convenient as the card swipe in the backseat of a cab is, and I am a huge user of the two TPEP systems, it pales in comparison to jumping out of the cab when you arrive and getting an instant email receipt,” Wilson said in a written statement. “If NYC wants to be a tech city and a leading hub of mobile and web innovation, it cannot let mobile checkout be hostage to last decade’s technology.”

But some of Hailo’s competitors have said they see no reason why their systems won’t work within the existing TLC rules.

“We haven’t pursued a waiver because the rules are workable and we haven’t had any issues,” said Travis Kalanick, CEO of Uber, in a statement provided by a spokesman. “We’re not under the impression that a waiver is even being offered given that the rules seem to be make sense and the various TPEP vendors are cooperating.”

Arguments in the livery industry’s lawsuit against the TLC are expected Feb. 28.